WASHINGTON (Reuters) - Very young children who eat French fries frequently have a much higher risk of breast cancer as adults, U.S. researchers reported on Wednesday.

A study of American nurses found that one additional serving of fries per week at ages three to five increased breast cancer risk by 27 percent.

"Researchers are finding more evidence that diet early in life could play a role in the development of diseases in women later in life," said Dr. Karin Michels, of Brigham and Women's Hospital in Boston and Harvard Medical School, who led the study.

Very young children who eat French fries frequently have a much higher risk of breast cancer as adults, U.S. researchers reported on Wednesday. An unidentified employee prepares fries behind the counter at a fast food outlet in a suburb east of Paris, August 8, 2005. (REUTERS/Jacky Naegelen/Files) "This study provides additional evidence that breast cancer may originate during the early phases of a woman's life and that eating habits during that phase may be particularly important to reduce future risk of breast cancer."

For their study, Michels and colleagues used an ongoing survey of female registered nurses. They studied 582 women with breast cancer and 1,569 women free of breast cancer in 1993.

Writing in the International Journal of Cancer, the researchers said they looked at the women's diets and at questionnaires filled out by the mothers of the participants.

One risk factor for breast cancer stood out: women whose mothers who said their daughters ate French fries had a higher risk of breast cancer. This increased 27 percent for each weekly serving reportedly eaten.

"These data have to be interpreted cautiously since the observed association between consumption of French fries and breast cancer is dependent on the validity of the maternal recall of the diet," said Michels.

"Mothers were asked to recall their daughter's preschool diet after the participants' breast cancer status was known and it is possible that mothers of women with breast cancer recalled their daughter's diet differently than mothers of healthy women," she added.

"Other foods perceived as less healthy such as hot dogs or ice cream however, were not associated with breast cancer risk."

A high-fat diet has been linked with breast cancer, which affects more than 200,000 U.S. women a year and is expected to kill 40,000 this year.